78 patients (61 females, 17 males) on the average of 73.2 years, showed statistically significant differences between piracetam therapy at a dosage of 3 X 1600 mg per day und placebo after a six week peroral therapy while no statistically significant differences between piracetam therapy at a dosage of 3X800 mg per day and placebo were found.

The subjects were given 3x4 capsules at 400 mg per day, in a double blind study. Each subject learned series of words presented as stimuli upon a memory drum. No effects were observed after 7 days but after 14 days verbal learning had significantly increased.

There were no significant statistical differences between the two groups of patients on all measures utilized except for the Clinical Global Evaluation, where 52% of the patients on piracetam showed minimal improvement versus 25% of the placebo group (P less than 0.05).

These effects are greatest between 1 and 4 h after dosage, and then diminish progressively to disappear between 8 and 12 h after administration. This explains the need to divide the total daily dose into 3 intakes at 8-hourly intervals. This study confirms the presence of four sites of action of piracetam: the vessel wall, platelets, plasma and cell membranes (RBC, WBC), which provide the basis for the potentially important antithrombotic activity of piracetam.

Three randomized parallel groups of 54 patients each, aged 55 years and over, were followed and treated for 3 months. After a placebo wash-out period of 10 days, one group received 2.4 g of piracetam, another group, 4.8g, and the third, a placebo. A total of 135 patients, 45 in each group, completed the study. Combined therapy was most effective in patients whose baseline performance on memory tests was lowest. The best results were observed with 4.8 g of piracetam, especially when training sessions began after 6 weeks of drug treatment.

Preincubation with piracetam enhanced the hydrocarbon core fluidity of hippocampal membranes from AD-patients as well as elderly controls in a concentration depending fashion, although the effect was more pronounced for the AD membranes.

While there may be problems in meta-analyses and the interpretation of the statistical results, the results of this analysis provide compelling evidence for the global efficacy of piracetam in a diverse group of older subjects with cognitive impairment.

In conclusion, therapeutically relevant in vitro and in vivo concentrations of piracetam are able to improve mitochondrial dysfunction associated with oxidative stress and/or aging. Mitochondrial stabilization and protection might be an important mechanism to explain many of piracetam's beneficial effects in elderly patients.

In Alzheimer's disease, i.v. administration of piracetam, 6 g b.i.d. for 2 weeks, significantly improved rCMRGlu in most cortical areas, whereas no effect on CMRGlu of the drug was observed in the multiinfarct dementia/unclassified dementia groups.

Inhibitory effect of piracetam on platelet-rich thrombus formation in an animal model.

Treatment with piracetam was initiated at a dose of 3.2 g/d that was gradually increased until stable benefit was noted (maximal dose in the trial was 20 g/d). Concomitant antiepileptic drugs were maintained at their previous dose.